I've just prepared a 1500mL starter last night and it kind of over-foamed during the night as I lost 50% of it in the sanitizer jar :(

The starter was prepared with 150g of DME into an 2000mL Erlenmeyer flask, with 1/2 tsp of yeast nutrients and 2x WLP001 California ale liquid yeast. I use continous aeration with the use of an aquarium pump+air filter+diffusion stone, and the stopper was also fitted with a blow-off tube reaching to a jar with sanitizer.

About 1 hour after I pitched the yeast and turned the pump on, the foam was already coming out the blow-off tube, and the next morning, HALF of it was in sanitizer...

My worry is about the yeast cell count.... Did most of the yeast in the high krauzen went out ? Can the remaining 800mL contain enough vigorous yeast to ferment my 10gal batch ?

Anyway, since I have to pitch today, I'll pitch only the clean remaining 800mL and see what happens.

Is there somenthing I did wrong ? Should I forget about continous aeration or use an oversized jar for the starter ? Is everything escaping by the blowoff unworthy anyway ?

I pitched the remaining of the starter into the fermenter.
After 36 hours, it only bubbles every 10 seconds. Hope I wont get a bad fermentation... If it doesn't get stronger, is there something I could do to help it, like giving it a wirl ?

kabbo wrote:I pitched the remaining of the starter into the fermenter.After 36 hours, it only bubbles every 10 seconds. Hope I wont get a bad fermentation... If it doesn't get stronger, is there something I could do to help it, like giving it a wirl ?

By 36 hours, I'd expect that it's too late to do much good by pitching more yeast. As long as the fermentation eventually takes hold and finishes, I'd just leave it alone at this point. Perhaps leave it in the fermentor a bit longer than usual to give the yeast a chance to clean up some of the byproducts they made during the extended growth phase. It might not be the best batch you ever brew, but I bet it will be good enough.

I've bought some foam control drops and just did a starter with it. Seems to do the job perfectly !

As for the last batch, it turns out OK after 1 month bottle conditionning, but there is some yeast off-flavor detectable, especially in such a relatively clean style that is Cream Ale. I get a weird after-taste similar to what I already had in a past batch, having boiled maple syrup for too long...
It blends with corn flavor and hop after-taste so, not so dramatic...

According to what I found on the internet, it seems to be frequent results of underpitching, but I don't know exactly how every off-flavor tastes like...Acetaldehyde? Alcoholic? Buttery? Phenolic? Solvent-like?

Yeah, I use a 4 L wine jug for 1.5-2 L starters to give me a lot of head space. Still, I usually get very little foam from a starter. I wonder what the difference is? Part of it is probably the narrow neck of an Erlenmeyer.

I now use a 4L plastic bottle (those used for spring water) for my 1,5-2L starters, but it still foams a lot even though I use foam drops. I don't know what's wrong, but maybe my aquarium pump is too strong or something. What I do is turning off the pump once it gets to the top of the bottle, just before it blows outside, and then shaking the bottle to get the foam and the yeast back in the wort. I did this every half hour or so during the brewday to keep it at high krausen and it worked out perfectly.